The primary objective of this predoctoral National Research Service Award program in Pharmacological Sciences is to develop scientists equipped with the necessary background in the basic biological and physical sciences, and training in the application of modern tools of research and instrumental techniques of the physical and biological sciences, to undertake and direct fundamental research related to drug action, metabolism and kinetics. These aspects include mechanisms by which drugs produce their effects on organisms and also the effects of biological systems on drugs, including the areas of drug distribution, bioavailability, metabolic processes, elimination and the study of kinetics of these processes. The training program would support Ph.D. student sin the broadly defined areas of drug metabolism, pharmacokinetics, cellular pharmacology and molecular pharmacology which presently exists in the departments of Medicinal Chemistry, Pharmaceutics and Pharmacology. Didactic components involved individualized, highly multi-disciplinary programs of coursework and seminars which involve the biological, chemical, spectroscopic and mathematical sciences. Research components of the training program will focus on the areas of the application and may involve collaborative research with other departments in the University. In this request for continuation of the Pharmacological Sciences National Research Service Award program, support is requested for 18 predoctoral trainees in the first year, 20 trainees in the third year and in subsequent years. The selection of trainees will be on a competitive basis primarily among second year or more advanced graduate students who are committed to research in one of these areas of the application.